32 DISCUSSION OF TIDES IN BOSTON HARBOR. 
TaBLE VII. 
| 
Month. u 2 g! My Ne HH H’, |:(H,+ H’.)/t(H';—H’.)| d Hy 
h. m. Feet. Feet. Feet. Feet. Feet. 
DEENA cote soocsuososbosaspsincesoscbosedsgac5 6 51.0 4, 933 5.190 20. 061 4. 861 —. 039 
February 6 52.2 4, 841 5. 060 19. 950 4. 890 —. 200 
March ..-. 6 53.4 4, 962 5. 058 20. 010 4, 952 —. 140 
April ..- 6 54.1 5. 000 5.177 20. 092 4.915 —. 058 
May ..- 6 55.5 5. 075 5. 253 20. 164 4.911 +. 014 
June. 6 57.8 5. 090 5. 225 20. 157 4. 932 +. 007 
July - 6 58.7 5. 082 5. 266 20.174 4. 908 +. 024 
August ....-.-...--- 6 57.8 5.113 5. 300 20. 206 4. 906 +. 056 
September 6 57.2 5. 091 5. 360 20. 225 4.865 | +.075 
October==-e-se——s— 6 54.5 5. 143 5. 469 20. 306 4. 837 +. 156 
November 6 53.3 5. 202 5. 425 20. 313 4, 888 +.163- 
December 6 50.8 5. 046 5. 240 20. 143 4.903 —.007 
6 54.9 8, 058 5. 202 20. 150 biel Waepocosiae~ 
From this table we obtain, as in preceding cases, twelve values of 6L, which, together with the 
corresponding values of v/ = 7, and 2 ¢g/ =7;, in (46) and (47), give twelve equations of the form 
OL= My, sin y4+ N, cos 44+ M; sin 75+ Ns; cos 75 
From these we get, in the same manner as in preceding cases, 
{ Bs =— 3.9, 24 == — 73° 
1B; —=— 0.6, &5—=— 10° 
In the sanie way with the values of $(H’; — H’2), (50) gives twelve equations of the form 
0H = Ky (My cos 44+ Ny sin 474+ Ms cos 75+ N; sin 75) 
(74) 
From these conditions we get 
(75) { K, Ry = 0.0378 ft., Ry =— .0077, a4 —=— 65° 
UK, R; = 0.0093 ft., R; = — .0019, a5 = — 58° 
In the same manner we obtain from the values of $(H,+ H’.), 
(76) § Ky Ry=0.126 ft., R,= 1.08, a4 = 2549 
( Ky Rs = 0.073 ft., R; = 0.62, ds;—= 98° 
Since the arguments in the preceding table change so little from high to the following low 
water, $(H’,;+H’,) may be taken as a normal yalue of the mean height, and 4 (H’,— H’,) as the 
coefficient or semi-range of the tide. 
In the preceding table 6H’, is the difference between any value of H’, and its mean value, and 
the column expresses the annual variation of mean level. 
INEQUALITY DEPENDING UPON THE MOON’S NODE. 
32. By summing the values of 24), 2/2, H;, and H's, and taking the averages so as to eliminate the 
annual inequalities, we obtain the following table of averages for each year, in which the value of 
w belonging to the middle of the year is given: 
